Police officers perform many duties relating to public safety. Their responsibilities include not only preserving the peace, preventing criminal acts, enforcing the law, investigating crimes, and arresting those who violate the law but also directing traffic, community relations work, and controlling crowds at public events. Police officers are employed at the federal, state, county, and city level.

State police officers patrol highways and enforce the laws and regulations that govern the use of those highways, in addition to performing general police work. Police officers are under oath to uphold the law 24 hours a day. There are approximately 635,380 police and sheriff's patrol officers employed in the United States.

Must be firearm qualified and free of felony convictions; pass a background investigation, drug test, psychological and medical examination; be a U.S. citizen; be at least 21; may not have any other health condition that might interfere with job performance or endanger the health and safety of others